Accounting Policies, by Policy (Policies)	6 Months Ended
Jun. 30, 2015
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Presentation The condensed consolidated financial statements included herein have been prepared by Sterling, without audit, in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) and should be read in conjunction with the 2014 Form 10-K. Certain information and note disclosures prepared in accordance with generally accepted accounting principles (“GAAP”) have been either condensed or omitted pursuant to SEC rules and regulations. The condensed consolidated financial statements reflect, in the opinion of management, all normal recurring adjustments necessary to present fairly the Company’s financial position at June 30, 2015 and the results of operations and cash flows for the periods presented. The December 31, 2014 condensed consolidated balance sheet data was derived from audited financial statements, but as discussed above, does not include all disclosures required by GAAP. Interim results may be subject to significant seasonal variations, and the results of operations for the three and six months ended June 30, 2015 are not necessarily indicative of the results to be expected for the full year or subsequent quarters.
Consolidation, Policy [Policy Text Block]	Principles of Consolidation The accompanying condensed consolidated financial statements include the accounts of subsidiaries and construction joint ventures in which the Company has a greater than 50% ownership interest or otherwise controls such entities. For investments in subsidiaries and construction joint ventures that are not wholly-owned, but where the Company exercises control, the equity held by the remaining owners and their portions of net income (loss) are reflected in the balance sheet line item “Noncontrolling interests” in “Equity” and the statement of operations line item “Noncontrolling owners’ interests in earnings of subsidiaries,” respectively. All significant intercompany accounts and transactions have been eliminated in consolidation. For all years presented, the Company had no subsidiaries where its ownership interests were less than 50%. Where the Company is a noncontrolling joint venture partner, and otherwise not required to consolidate the joint venture entity, its share of the operations of such construction joint venture is accounted for on a pro rata basis in the condensed consolidated statements of operations and as a single line item (“Receivables from and equity in construction joint ventures”) in the condensed consolidated balance sheets. This method is an acceptable modification of the equity method of accounting which is a common practice in the construction industry. Refer to Note 3 for further information regarding the Company’s construction joint ventures. Under U.S. GAAP, the Company must determine whether each entity, including joint ventures in which it participates, is a variable interest entity (“VIE”). This determination focuses on identifying which owner or joint venture partner, if any, has the power to direct the activities of the entity and the obligation to absorb losses of the entity or the right to receive benefits from the entity disproportionate to its interest in the entity, which could have the effect of requiring us to consolidate the entity in which we have a noncontrolling variable interest. Refer to Note 10 for further information regarding the Company’s consolidated VIE.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates The preparation of the accompanying condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Certain of the Company’s accounting policies require higher degrees of judgment than others in their application. These include the recognition of revenue and earnings from construction contracts under the percentage-of-completion method, the valuation of long-term assets (including goodwill), and income taxes. Management continually evaluates all of its estimates and judgments based on available information and experience; however, actual results could differ from these estimates.
Reclassification, Policy [Policy Text Block]	Reclassification A reclassification has been made to historical financial data on our condensed consolidated statement of cash flow to conform to our current year presentation.
Revenue Recognition, Percentage-of-Completion Method [Policy Text Block]	Revenue Recognition The Company is a general contractor which engages in various types of heavy civil construction projects principally for public (government) owners. Credit risk is minimal with public owners since the Company ascertains that funds have been appropriated by the governmental project owner prior to commencing work on such projects. While most public contracts are subject to termination at the election of the government entity, in the event of termination the Company is entitled to receive the contract price for completed work and reimbursement of termination-related costs. Credit risk with private owners is minimized because of statutory mechanic’s liens, which give the Company high priority in the event of lien foreclosures following financial difficulties of private owners. Revenues are recognized on the percentage-of-completion method, measured by the ratio of costs incurred up to a given date to estimated total costs for each contract. This cost to cost measure is used because management considers it to be the best available measure of progress on these contracts. Contract costs include all direct material, labor, subcontract and other costs and those indirect costs related to contract performance, such as indirect salaries and wages, equipment repairs and depreciation, insurance and payroll taxes. Administrative and general expenses are charged to expense as incurred. Provisions for estimated losses on uncompleted contracts are made in the period in which such losses are determined. Changes in job performance, job conditions and estimated profitability, including those changes arising from contract penalty provisions and final contract settlements may result in revisions to costs and income and are recognized in the period in which the revisions are determined. Changes in estimated revenues and gross margin resulted in a net gain of $0.9 million and a net charge of $11.2 million during the three months and six months ended June 30, 2015, respectively, included in Operating (loss) income, or $0.04 and $(0.59) per diluted share attributable to Sterling common stockholders, respectively, included in Net (loss) income attributable to Sterling common stockholders. Changes in estimated revenues and gross margin resulted in a net gain of $2.3 million and $5.0 million during the three months and six months ended June 30, 2014, respectively, included in Operating (loss) income, or $0.12 and $0.27 per diluted share attributable to Sterling common stockholders, respectively, included in Net (loss) income attributable to Sterling common stockholders. Our contracts generally take 12 to 36 months to complete. The Company generally provides a one to two-year warranty for workmanship under its contracts when completed. Warranty claims historically have been insignificant.
Fair Value of Financial Instruments, Policy [Policy Text Block]	Financial Instruments and Fair Value The fair value of financial instruments is the amount at which the instrument could be exchanged in a current transaction between willing parties. The Company’s financial instruments are cash and cash equivalents, restricted cash used as collateral for a letter of credit, short-term and long-term contracts receivable, derivatives, accounts payable, mortgage and notes payable, a revolving loan (the “Revolving Loan”) with Nations Fund I, LLC and Nations Equipment Finance, LLC, as administrative agent and collateral agent for the lender (“Nations”), a term loan (the “Term Loan”) with Nations, and an earn-out liability related to the acquisition of J. Banicki Construction, Inc. (“JBC”). The recorded values of cash and cash equivalents, and restricted cash used as collateral for a letter of credit, short-term contracts receivable and accounts payable approximate their fair values based on their short-term nature. The recorded value of long-term contracts receivable is based on the amount of future cash flows discounted using the creditor’s borrowing rate and such recorded value approximates fair value. We currently have one long-term contract receivable which is discounted at 4.25% and recorded at fair value. Interest earned related to the long-term contract receivable was $0.1 million for the three and six months ended June 30, 2015, respectively, and $0.1 million and $0.2 million for the three and six months ended June 30, 2014, respectively. Refer to Note 5 regarding the fair value of derivatives, Note 8 regarding the fair value of an earn-out liability along with the most current amendments, and Note 12 regarding the fair value of the Revolving Loan and the Term Loan. The Company had one mortgage outstanding at December 31, 2014 with a remaining balance of $0.1 million and was fully paid in June 2015. At December 31, 2014, the fair value of the mortgage approximated book value. The Company also has long-term notes payable of $2.8 million related to machinery and equipment purchased which have payment terms ranging from 3 to 5 years and associated interest rates ranging from 3.12% to 6.29%. The fair value of the notes payable approximates their book value. The Company does not have any off-balance sheet financial instruments other than operating leases (refer to Note 14 of the Notes to Consolidated Financial Statements in the 2014 Form 10-K). In order to assess the fair value of the Company’s financial instruments, the Company uses the fair value hierarchy established by GAAP which prioritizes the inputs used in valuation techniques into the following three levels: Level 1 Inputs – Based upon quoted prices for identical assets in active markets that the Company has the ability to access at the measurement date. Level 2 Inputs – Based upon quoted prices (other than Level 1) in active markets for similar assets, quoted prices for identical or similar assets in markets that are not active, inputs other than quoted prices that are observable for the asset such as interest rates, yield curves, volatilities and default rates and inputs that are derived principally from or corroborated by observable market data. Level 3 Inputs – Based on unobservable inputs reflecting the Company’s own assumptions about the assumptions that market participants would use in pricing the asset based on the best information available. For each financial instrument, the Company uses the highest priority level input that is available in order to appropriately value that particular instrument. In certain instances, Level 1 inputs are not available and the Company must use Level 2 or Level 3 inputs. In these cases, the Company provides a description of the valuation techniques used and the inputs used in the fair value measurement.
Out of Period Adjustment Description [Policy Text Block]	Out-of-Period Adjustment During the first quarter of 2015, the Company recorded a $2.8 million out-of-period decrease in revenue that affected our results of operations for the six months ended June 30, 2015. The adjustment was identified during our first quarter review of projects. Management evaluated the effect of the adjustment on the Company’s financial statements based on SEC Staff Accounting Bulletin (“SAB”) No. 99 and SAB 108 and concluded that it was immaterial to the current and prior year’s financial statements.
New Accounting Pronouncements, Policy [Policy Text Block]	Recent Accounting Pronouncements In April 2015, the Financial Accounting Standards Board (“FASB”) issued an Accounting Standards Update (“ASU”) 2015-03, “Interest - Imputation of Interest: Simplifying the Presentation of Debt Issuance Costs.” The guidance, which is effective for annual reporting periods beginning after December 15, 2015 and interim periods within annual periods beginning after December 15, 2015, requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The adoption of this ASU requires retrospective application to all periods presented. Although early adoption is permitted, the Company expects to adopt this guidance when required and expects a change in the presentation of our consolidated balance sheets and related disclosures. The Company does not expect a material impact to the consolidated statements of operations. In February 2015, the FASB issued ASU 2015-02, “Consolidation: Amendments to the Consolidation Analysis.” The guidance, which is effective for annual reporting periods beginning after December 15, 2015 and interim periods within annual periods beginning after December 15, 2015, modifies the analysis that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. Early adoption is permitted. The Company does not expect a material impact to the Company’s consolidated financial statements and related disclosures. In August 2014, the FASB issued ASU 2014-15, “Presentation of Financial Statement – Going Concern.” The guidance, which is effective for annual reporting periods ending after December 15, 2016 and interim periods within annual periods beginning after December 15, 2016, requires management to evaluate whether there is substantial doubt about the entity’s ability to continue as a going concern and to provide related footnote disclosures. Early adoption is permitted. Although early adoption is permitted, the Company expects to adopt this guidance as required and does not expect a material impact to the Company’s consolidated financial statements. In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers.” The guidance defines the steps to recognize revenue for entities that have contracts with customers. In July 2015, the FASB voted to defer the effective date of this ASU by one year. As a result, the amendments in ASU 2014-09 are effective for public companies for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Entities would be permitted to adopt this ASU as early as the original public entity effective date, which was annual reporting periods beginning after December 15, 2016 and interim periods therein. Early adoption prior to that date would not be permitted. The Company is currently evaluating the impact of the adoption of this ASU to the Company’s consolidated financial statements and related disclosures.

Accounting Policies, by Policy (Policies)

6 Months Ended

Jun. 30, 2015

Basis of Accounting, Policy [Policy Text Block]

Presentation

The condensed consolidated financial statements included herein have been prepared by Sterling, without audit, in accordance with the rules and regulations of the Securities and Exchange Commission (“SEC”) and should be read in conjunction with the 2014 Form 10-K. Certain information and note disclosures prepared in accordance with generally accepted accounting principles (“GAAP”) have been either condensed or omitted pursuant to SEC rules and regulations. The condensed consolidated financial statements reflect, in the opinion of management, all normal recurring adjustments necessary to present fairly the Company’s financial position at June 30, 2015 and the results of operations and cash flows for the periods presented. The December 31, 2014 condensed consolidated balance sheet data was derived from audited financial statements, but as discussed above, does not include all disclosures required by GAAP. Interim results may be subject to significant seasonal variations, and the results of operations for the three and six months ended June 30, 2015 are not necessarily indicative of the results to be expected for the full year or subsequent quarters.

Consolidation, Policy [Policy Text Block]

Principles of Consolidation

The accompanying condensed consolidated financial statements include the accounts of subsidiaries and construction joint ventures in which the Company has a greater than 50% ownership interest or otherwise controls such entities. For investments in subsidiaries and construction joint ventures that are not wholly-owned, but where the Company exercises control, the equity held by the remaining owners and their portions of net income (loss) are reflected in the balance sheet line item “Noncontrolling interests” in “Equity” and the statement of operations line item “Noncontrolling owners’ interests in earnings of subsidiaries,” respectively. All significant intercompany accounts and transactions have been eliminated in consolidation. For all years presented, the Company had no subsidiaries where its ownership interests were less than 50%.

Where the Company is a noncontrolling joint venture partner, and otherwise not required to consolidate the joint venture entity, its share of the operations of such construction joint venture is accounted for on a pro rata basis in the condensed consolidated statements of operations and as a single line item (“Receivables from and equity in construction joint ventures”) in the condensed consolidated balance sheets. This method is an acceptable modification of the equity method of accounting which is a common practice in the construction industry. Refer to Note 3 for further information regarding the Company’s construction joint ventures.

Under U.S. GAAP, the Company must determine whether each entity, including joint ventures in which it participates, is a variable interest entity (“VIE”). This determination focuses on identifying which owner or joint venture partner, if any, has the power to direct the activities of the entity and the obligation to absorb losses of the entity or the right to receive benefits from the entity disproportionate to its interest in the entity, which could have the effect of requiring us to consolidate the entity in which we have a noncontrolling variable interest. Refer to Note 10 for further information regarding the Company’s consolidated VIE.

Use of Estimates, Policy [Policy Text Block]

Use of Estimates

The preparation of the accompanying condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Certain of the Company’s accounting policies require higher degrees of judgment than others in their application. These include the recognition of revenue and earnings from construction contracts under the percentage-of-completion method, the valuation of long-term assets (including goodwill), and income taxes. Management continually evaluates all of its estimates and judgments based on available information and experience; however, actual results could differ from these estimates.

Reclassification, Policy [Policy Text Block]

Reclassification

A reclassification has been made to historical financial data on our condensed consolidated statement of cash flow to conform to our current year presentation.

Revenue Recognition, Percentage-of-Completion Method [Policy Text Block]

Revenue Recognition

The Company is a general contractor which engages in various types of heavy civil construction projects principally for public (government) owners. Credit risk is minimal with public owners since the Company ascertains that funds have been appropriated by the governmental project owner prior to commencing work on such projects. While most public contracts are subject to termination at the election of the government entity, in the event of termination the Company is entitled to receive the contract price for completed work and reimbursement of termination-related costs. Credit risk with private owners is minimized because of statutory mechanic’s liens, which give the Company high priority in the event of lien foreclosures following financial difficulties of private owners.

Revenues are recognized on the percentage-of-completion method, measured by the ratio of costs incurred up to a given date to estimated total costs for each contract. This cost to cost measure is used because management considers it to be the best available measure of progress on these contracts. Contract costs include all direct material, labor, subcontract and other costs and those indirect costs related to contract performance, such as indirect salaries and wages, equipment repairs and depreciation, insurance and payroll taxes. Administrative and general expenses are charged to expense as incurred. Provisions for estimated losses on uncompleted contracts are made in the period in which such losses are determined. Changes in job performance, job conditions and estimated profitability, including those changes arising from contract penalty provisions and final contract settlements may result in revisions to costs and income and are recognized in the period in which the revisions are determined.

Changes in estimated revenues and gross margin resulted in a net gain of $0.9 million and a net charge of $11.2 million during the three months and six months ended June 30, 2015, respectively, included in Operating (loss) income, or $0.04 and $(0.59) per diluted share attributable to Sterling common stockholders, respectively, included in Net (loss) income attributable to Sterling common stockholders. Changes in estimated revenues and gross margin resulted in a net gain of $2.3 million and $5.0 million during the three months and six months ended June 30, 2014, respectively, included in Operating (loss) income, or $0.12 and $0.27 per diluted share attributable to Sterling common stockholders, respectively, included in Net (loss) income attributable to Sterling common stockholders.

Our contracts generally take 12 to 36 months to complete. The Company generally provides a one to two-year warranty for workmanship under its contracts when completed. Warranty claims historically have been insignificant.

Fair Value of Financial Instruments, Policy [Policy Text Block]

Financial Instruments and Fair Value

The fair value of financial instruments is the amount at which the instrument could be exchanged in a current transaction between willing parties. The Company’s financial instruments are cash and cash equivalents, restricted cash used as collateral for a letter of credit, short-term and long-term contracts receivable, derivatives, accounts payable, mortgage and notes payable, a revolving loan (the “Revolving Loan”) with Nations Fund I, LLC and Nations Equipment Finance, LLC, as administrative agent and collateral agent for the lender (“Nations”), a term loan (the “Term Loan”) with Nations, and an earn-out liability related to the acquisition of J. Banicki Construction, Inc. (“JBC”).

The recorded values of cash and cash equivalents, and restricted cash used as collateral for a letter of credit, short-term contracts receivable and accounts payable approximate their fair values based on their short-term nature. The recorded value of long-term contracts receivable is based on the amount of future cash flows discounted using the creditor’s borrowing rate and such recorded value approximates fair value. We currently have one long-term contract receivable which is discounted at 4.25% and recorded at fair value. Interest earned related to the long-term contract receivable was $0.1 million for the three and six months ended June 30, 2015, respectively, and $0.1 million and $0.2 million for the three and six months ended June 30, 2014, respectively.

Refer to Note 5 regarding the fair value of derivatives, Note 8 regarding the fair value of an earn-out liability along with the most current amendments, and Note 12 regarding the fair value of the Revolving Loan and the Term Loan. The Company had one mortgage outstanding at December 31, 2014 with a remaining balance of $0.1 million and was fully paid in June 2015. At December 31, 2014, the fair value of the mortgage approximated book value. The Company also has long-term notes payable of $2.8 million related to machinery and equipment purchased which have payment terms ranging from 3 to 5 years and associated interest rates ranging from 3.12% to 6.29%. The fair value of the notes payable approximates their book value. The Company does not have any off-balance sheet financial instruments other than operating leases (refer to Note 14 of the Notes to Consolidated Financial Statements in the 2014 Form 10-K).

In order to assess the fair value of the Company’s financial instruments, the Company uses the fair value hierarchy established by GAAP which prioritizes the inputs used in valuation techniques into the following three levels:

Level 1 Inputs – Based upon quoted prices for identical assets in active markets that the Company has the ability to access at the measurement date.

Level 2 Inputs – Based upon quoted prices (other than Level 1) in active markets for similar assets, quoted prices for identical or similar assets in markets that are not active, inputs other than quoted prices that are observable for the asset such as interest rates, yield curves, volatilities and default rates and inputs that are derived principally from or corroborated by observable market data.

Level 3 Inputs – Based on unobservable inputs reflecting the Company’s own assumptions about the assumptions that market participants would use in pricing the asset based on the best information available.

For each financial instrument, the Company uses the highest priority level input that is available in order to appropriately value that particular instrument. In certain instances, Level 1 inputs are not available and the Company must use Level 2 or Level 3 inputs. In these cases, the Company provides a description of the valuation techniques used and the inputs used in the fair value measurement.

Out of Period Adjustment Description [Policy Text Block]

Out-of-Period Adjustment

During the first quarter of 2015, the Company recorded a $2.8 million out-of-period decrease in revenue that affected our results of operations for the six months ended June 30, 2015. The adjustment was identified during our first quarter review of projects. Management evaluated the effect of the adjustment on the Company’s financial statements based on SEC Staff Accounting Bulletin (“SAB”) No. 99 and SAB 108 and concluded that it was immaterial to the current and prior year’s financial statements.

New Accounting Pronouncements, Policy [Policy Text Block]

Recent Accounting Pronouncements

In April 2015, the Financial Accounting Standards Board (“FASB”) issued an Accounting Standards Update (“ASU”) 2015-03, “Interest - Imputation of Interest: Simplifying the Presentation of Debt Issuance Costs.” The guidance, which is effective for annual reporting periods beginning after December 15, 2015 and interim periods within annual periods beginning after December 15, 2015, requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The adoption of this ASU requires retrospective application to all periods presented. Although early adoption is permitted, the Company expects to adopt this guidance when required and expects a change in the presentation of our consolidated balance sheets and related disclosures. The Company does not expect a material impact to the consolidated statements of operations.

In February 2015, the FASB issued ASU 2015-02, “Consolidation: Amendments to the Consolidation Analysis.” The guidance, which is effective for annual reporting periods beginning after December 15, 2015 and interim periods within annual periods beginning after December 15, 2015, modifies the analysis that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. Early adoption is permitted. The Company does not expect a material impact to the Company’s consolidated financial statements and related disclosures.

In August 2014, the FASB issued ASU 2014-15, “Presentation of Financial Statement – Going Concern.” The guidance, which is effective for annual reporting periods ending after December 15, 2016 and interim periods within annual periods beginning after December 15, 2016, requires management to evaluate whether there is substantial doubt about the entity’s ability to continue as a going concern and to provide related footnote disclosures. Early adoption is permitted. Although early adoption is permitted, the Company expects to adopt this guidance as required and does not expect a material impact to the Company’s consolidated financial statements.

In May 2014, the FASB issued ASU 2014-09, “Revenue from Contracts with Customers.” The guidance defines the steps to recognize revenue for entities that have contracts with customers. In July 2015, the FASB voted to defer the effective date of this ASU by one year. As a result, the amendments in ASU 2014-09 are effective for public companies for annual reporting periods beginning after December 15, 2017, including interim periods within that reporting period. Entities would be permitted to adopt this ASU as early as the original public entity effective date, which was annual reporting periods beginning after December 15, 2016 and interim periods therein. Early adoption prior to that date would not be permitted. The Company is currently evaluating the impact of the adoption of this ASU to the Company’s consolidated financial statements and related disclosures.

- Definition

Disclosure of accounting policy for revenue recognition for long-term construction-type contracts accounted for using the percentage-of-completion method. The disclosure would generally be expected to include the method or methods of measuring extent of progress toward completion. If the entity departs from using the percentage-of-completion method for a single contract or a group of contracts for which reasonably dependable estimates cannot be made, such a departure from the basic policy is disclosed. The disclosure may also describe the accounting for significant changes in estimate.

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